Note: Descriptions are shown in the official language in which they were submitted.
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1'~E~I~F1L~~~ H~~~IE~C II'~T~ECTII~I~T ~L~~C1E KITH I~~T~h~T-ElLECT~T1C
PIE' 11~~' I~I'~Tl~I'~T I~~
FIEFD OF THE II~TTI~i'
[0001] The invention concerns a needleless hypodermic injection device for
delivering
liquid medication contained in the device. The device includes pyrotechnical
means
therein for generating a pressure necessary for injecting the medication. An
ignition
means ignites a propellant contained withinin the device.
BACKGROUND OF THE INVENTION
[0002] U.S. Patent No. 6,25,063 discloses a needleless hypodermic injection
device
comprising electric ignition means for igniting a propellant contained in the
device and
thereby.generating the gas pressure necessary for performing the injection.
Electric
ignition requires the use of batteries as source of energy. Use of batteries
is
disadvantageous, because disposal of batteries in normal trash is not allowed
due to
environmental concerns. Thus electric ignition is not a suitable solution for
a needleless
injection device that should be disposable in normal trash after a single or
at most a few
injections performed therewith. Moreover, it is wasteful to discard the entire
injection
device with its battery after a single use, because the battery could still be
used for
performing more than a single injection.
[0003] Heavy metal-free impact sensitive pyrotechnic ignition primers provide
an
environmentally acceptable means of igniting propellant. Typically, a cocked
spring
and firing pin are released by a trigger to strike and ignite impact sensitive
pyrotechnic
ignition material. The heat and products of combustion of~the ignition
material in turn
ignite the propellant. A variety of such primers is known in the art, and may
be
purchased or manufactured at low cost.
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[0004] A problem with utilizing such primers in a single use disposable device
is the need
to provide a firing pin, spring and trigger mechanism that functions reliably,
yet has
low manufacturing cost.
[000] Another problem with utilizing such primers is the integration of the
primer and the
firing pin, spring and trigger mechanism with the injection device such that
the total
system is structurally sound, leak-tight and compact. The magnitude of these
problems
increases as the firing pin mechanical energy requirement increases.
S ~ ~F TFIE I ~TTI~hT
(0006] The invention herein solves the above-mentioned problems and thereby to
reduce
the manufacturing cost of the injection device and to maintain and preferably
even
increase the reliability of operation of the latter device.
[0007] The invention concerns in particular a device of the above mentioned
kind wherein
the device comprises a stab primer device as part of the ignition means.
[0008] Within the scope of the instant invention, a propellant is a
pyrotechnic fuel which
mainly contributes to the delivery of thermal energy and gas production of a
pyrotechnic system.
[0009] Within the scope of the instant invention, a stab primer ignition means
is an
assembly that contains at least a sensitive primary pyrotechnic initiator
material that is
mechanically ignited by the direct impact and friction of a penetrating firing
pin. It may
also contain secondary pyrotechnic ignition materials and propellant that are
ignited in
a chain of events started by the ignition of the primary pyrotechnic initiator
material.
Further, it may be part of a unitary package that includes an outer container
and seals
that protect the pyrotechnic materials from external effects such as
atmospheric
moisture.
(0010] The above-mentioned problems are solved by using a primer device
comprising a
primer material which is adapted to be ignited by friction of the primer
material with a
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mechanical frictional element. In a preferred embodiment, the frictional
element is an
elongated rod a portion of which is embedded in the primer material and the
outer
surface of the portion has serrations that cause frictional forces when the
rod portion is
pulled out of the primer material. In preferred e~xabodiments, the primer
device used is
a stab primer device.
[0011] The main advantages of a device 'according to the invention are
obtained by the use
of primer devices of the above mentioned kind and in particular by the use of
stab
primer devices as part of the ignition means, because activation of stab
primers
requires very low mechanical energy. They typically fire reliably with less
than 10
millijoules firing pin energy. In comparison, primers used in centerfire
pistol
ammunition require 150 millijoules.
[0012] Commercially manufactured stab primers are cylindrical assemblies
ranging from 2
to 6 millimeters in diameter and 4 to 12 millimeters in length. There are two
basic
configurations available. The outer package of the first is a metallic cup.
These one-
side-open igniters are struck and ignited by a firing pin traveling along the
cylindrical
axis and entering the open end of the cup. The pr~ducts of combustion then
flow out
through the open cup end around the firing pin, while the other end remains
sealed.
The outer package of the second is a metallic tube. These two-side-open
igniters are
struck and ignited by a firing pin traveling along the cylindrical axis and
entering one
open end of the tube. The products of combustion then flow out of both open
ends.
[0013] In preferred embodiments in which the primer device is a stab primer
device, the
latter device contains a firing pin and a bistable spring for driving the
firing pin so that
it penetrates a primer material contained in the stab primer device.
[0014] According to a first aspect of the invention, a needleless hypodermic
injection
device for delivering a liquid medication contained therein includes
pyrotechnical
means for generating within the device a pressure necessary for injecting the
medication and the device comprises ignition means for igniting a propellant
contained
in the device. The device further comprises a stab primer device and a firing
pin for
penetrating. a stab primer material stationarily arranged within the stab
primer device.
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The stab primer material is so positioned with respect to the propellant that
when the
fixing pin penetrates the primer material, hot products of combustion of the
primer
material are generated and these products ignite the propellant.
[001] In a preferred embodiment, the latter device further comprises a spring
for urging
the firing pin towards the primer material, and a release latch for holding
the spring in
a loaded position and thereby the firing pin in a cocked position and for
releasing the
spring and thereby drive the firing pin towards the primer material. The stab
primer
device preferably comprises a stab primer open on two sides opposite to each
other.
[0016] According to a second aspect of the invention, a needleless hypodermic
injection
device for delivering a liquid medication contained therein includes
pyrotechnical
means for generating within the device a pressure necessary for injecting the
medication and the device comprises ignition means for igniting a propellant
contained
in the device. The device further comprises
a slidably mounted stab primer device which is open on only one side and with
the
open side arranged in face of a sharp point of a stationary stab pin,
an impact plunger for driving the stab primer device towards the stab pin so
that the
pin penetrates into a primer material.contained in the stab primer device,
a spring for urging the plunger towards the primer material, and
a release latch for releasably holding the spring and thereby the plunger in a
cocked
position.
[0017] In a first preferred embodiment, the device disclosed immediately above
further
comprises release means for releasing the release latch. The release means
preferably
comprise a breakable crimp joint or a breakable rod.
[0018] According to a third aspect of the invention, in a preferred embodiment
of the
device according to the above-mentioned second aspect of the invention, the
impact
plunger comprises a tapered section and a hook for setting the plunger in a
cocked
position, and the release latch is a release lever for releasing the hook and
for thereby
releasing the impact plunger from the cocked position.
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[0019] According to a fourth aspect of the invention, a needleless hypodermic
injection
device for delivering liquid medication contained therein includes
pyrotechnical means
for generating within the device a pressure necessary for injectixag the
medication and
the device comprises ignition means for igniting a, propellant contained in
the device.
The device further comprises a st~.b primer device and a firing pin for
penetrating a
stab primer material stationarily arranged within the stab primer device. The
stab
primer material is so positioned with respect to the propellant that when the
firing pin
penetrates the primer material, hot products of combustion of the primer
material are
generated and these products ignite the propellant. The device further
comprises a
bistable spring for urging the firing pin towards the primer material, the
bistable spring
being adapted to snap at a transition point from a first stable position to a
second stable
position. In a first preferred embodiment of the latter device the bistable
spring and the
firing pin are integral part of the structure of the stab primer.
[0020] In a second preferred embodiment of the device disclosed immediately
above, it
further comprises an actuation screw which when turned in a predetermined
position
pushes the bistable spring and the firing pin towards the primer material and
thereby
brings the spring to the transition point where it snaps from the first to the
second
position, the latter snapping causing the firing pin to penetrate and ignite
the primer
material.
[0021] According to a fifth aspect of the invention, in a third preferred
embodiment of the
device according to the above-mentioned fourth aspect of the invention, the
device
further comprises an actuation push pin which when axially displaced in a
predetermined position, pushes the bistable spring and the firing pin towards
the primer
material and thereby brings the spring to the transition point where it snaps
from the
first to the second position, the latter snapping causes the firing pin to
penetrate and
ignite the primer. The bistable spring preferably seals an opening of the stab
primer
device.
[0022] In a preferred embodiment of the device according to the fifth aspect
of the
invention, the device further comprises a venting passage which fluidically
connects
spaces on opposite sides of the bistable spring and thereby enables gas flow
around the
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bistable spring. The bistable spring has preferably the shape of a disk. In a
preferred
embodiment the bistable spring comprises vents that equalise pressure on both
sides of
the disk. In another preferred en~bodixnent the ignition means is an integral
part of a
pre-assen2blecl ga.s generator module.
[0023] According to a sixth aspect of the invention, a needleless hypodermic
injection
device for delivering liquid medication contained therein includes
pyrotechnical means
for generating within the device a pressure necessary for injecting the
medication and
the device comprises ignition means for igniting a propellant contained in the
device.
The device further comprises a stab primer device and a firing pin for
penetrating a
stab primer material stationarily arranged within the stab primer device. The
stab
primer material is so positioned with respect to the propellant that when the
firing pin
penetrates the primer material, hot products of combustion of the primer
material are
generated and these products ignite the propellant. The firing pin ends in a
firing pin
head located within a closed chamber, which seals a space of limited volume
located
between the firing pin head and one side of the stab primer.
[0024] According to a seventh aspect of the invention, a needleless hypodermic
injection
device for delivering liquid medication contained therein. includes
pyrotechnical means
for generating within the device a pressure necessary for injecting the
medication and
the device comprises ignition means for igniting a propellant contained in the
device.
The device further comprises a stab primer device and a firing pin for
penetrating a
stab primer material stationarily arranged within the stab primer device. The
stab
primer material is so positioned with respect to the propellant that when the
firing pin
penetrates the primer material, hot products of combustion of the primer
material are
generated and these products ignite the propellant. The device further
comprises a
spring for urging the firing pin towards the primer material, and a release
mechanism
for holding the spring in a loaded position, and thereby the firing pin in a
cocked
position and for releasing the spring and thereby drive the firing pin towards
the primer
material.
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[0025] In a preferred embodiment of the latter device the firing pin, the
spring and the
release mechanism are located in a closed space into which hot gases generated
by
ignition of the primer material and the propellant flow.
[0026] In a further preferred embodiment, the release mechanism comprises
means for
rotating the firing pin using torque applied by means which is located outside
the
device. This rotation brings the firing pin from a first angular position
where it is in a
cocked position to a second angular position where the pin is free to move
axially and
making contact with the primer material.
[0027] According to a eighth aspect of the invention, in a preferred
embodiment of the
device according to the above-mentioned seventh aspect of the invention, the
release
mechanism of the device comprises a shaft adapted to be twisted from a first
angular
position to a second angular position for releasing the spring. The shaft is
in contact
with the firing pin in the cocked position thereof, but is mechanically
disconnected
therefrom so that when the firing pin is released from its cocked position and
moves
towards the primer material, the shaft does not move with the firing pin. In a
preferred
embodiment, the shaft includes flange means, which seal an annular opening
around the
shaft when pressure pushes the shaft to the rear of the device. In a further
preferred
embodiment, the ignition means is an integral part of a preassembled gas
generator
module.
(0028] According to a ninth aspect of the invention, a needleless hypodermic
injection
device for delivering liquid medication contained therein comprises
(a) a cartridge which contains ,
(a. l) a medication unit containing the liquid medication,
(a.2) pyrotechnical means for generating within the device a pressure
necessary
for injecting the medication, and
(a.3) ignition means for igniting a propellant contained in the device, and
(b) a spring and trigger mechanism for striking the firing pin with such an
impact
that it strikes and penetrates the primer material.
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[0029] The spring and trigger mechanism are located outside the cartridge. The
ignition
means comprises a stab primer device and a firing pin for penetrating a stab
primer
material stationarily arranged within the device. The stab primer material is
so
positioned with respect to the propellant that when the firing pin penetrates
the primer
material, hot products of combustion of the primer material are generated and
these
products ignite the propellant.
[0030] Tn a preferred embodiment, the firing pin is slidably arranged in a
bore of a housing
part of the cartridge. A portion of the inner wall of the bore has ratchet
fingers. A part
of the firing pin is a shaft a portion ~f which has a ratchet grooves. The
ratchet fingers
and the ratchet grooves are adapted to cooperate with each other to allow
motion of the
firing pin towards the primer material, but to prevent motion of the firing
pin away
from the primer material after ignition thereof.
[0031] In a preferred embodiment, the ignition means is an integral part of a
preassembled
gas generator module.
[0032] In all the above mentioned embodiments comprising a stab primer device,
the entire
amount of propellant in the device is preferably located within the stab
primer device.
However, for particular applications the device may comprise an amount of
propellant
located outside of the stab primer device.
[0033] Any and all the above mentioned embodiments are suitable for being used
as part of
a first type of device which comprises
(a) a housing,
(b) a first chamber within the housing, the' first chamber containing a
medication
unit configured and dimensioned to store a volume of liquid medication to be
injected,
the medication unit having a first region and a second region that are in
liquid
communication with each other, the first region being deformable and the
second
region having an ejection outlet, and
(c) a second chamber within the housing, the second chamber containing a
propellant,
the first chamber comprising two. cones, a first gone containing the
medication unit
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and a second zone which is in communication with the second chamber, so that
upon
ignition of the pr~pellant in the second chamber gas generated thereby expands
into the
second z~ne of the first chamber, exerts pressure on and deforms the
deformable first
region of the medication unit and thereby causes ejection of the liquid
medication
through the ejecti~n outlet.
[003] In a preferred embodiment of this first type of device, the propellant
is contained in
a propellant chamber having a wall which has a zone of reduced thickness which
upon
ignition of the propellant bursts and thereby forms an opening of the wall
when gas
pressure within the propellant chamber exceeds a predetermined value.
[0035] Any and all the above mentioned embodiments are suitable for being used
as part of
a second type of device which comprises a nozzle body, and a rigid housing.
The
housing has a first open end adapted to receive and be connected with the
nozzle body
and a second closed end. The interior of the housing defines a chamber which
extends
between the open end and the closed end of the housing. The chamber is adapted
to
receive a first deformable diaphragm which together with a cavity of the
nozzle body
forms a medication chamber suitable for receiving a predetermined amount of a
medication, and a second deformable diaphragm a portion of which extends
around a
portion of the first deformable diaphragm. The second deformable diaphragm and
the
housing form together a chamber for receiving a propellant as well as means
for
igniting the propellant. The nozzle body has at its outer end an orifice which
is the
outlet of a channel for ejecting the medication out of the chamber when a gas
pressure
generated by ignition of the propellant is applied to the second deformable
diaphragm
and thereby to the first deformable diaphragm.
[0036] In a preferred embodiment, the nozzle body and the housing are
connected to form
a single structural shell.
[0037] In another preferred embodiment, the device further comprises venting
means for
venting of the space comprised between the first deformable diaphragm and the
second
deformable diaphragm.
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[0038] In a further preferred embodiment, the device does not include the
second
deformable diaphragm.
[003] Any and all the ~.bove menti~ned embodiments are suitable for being used
as part of
a third type of device which comprises
(a) a rigid medication container having a medication zone f~r receiving the
liquid
mediCatlon,
(b) a nozzle in fluitlic communication with the medication zone, the nozzle
having
an outlet orifice,
(c) a propellant zone where the propellant is located within the device,
(d) a channel that fluidically connects the propellant zone with the
medication zone,
and
(e) piston means slidably arranged within the channel, so that upon ignition
of the
propellant gas pressure generated by combustion of the propellant causes
displacement
of the piston means which then exert pressure on the liquid medication and
eject it
through the outlet orifice of the nozzle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0040] The subject of the invention will now be described in terms of its
preferred
embodiments with reference to the accompanying drawings. These embodiments are
set
forth to aid the understanding of the invention, but are not to be construed
as limiting.
[0041] Fig. 1 shows a cross-sectional view of a first embodiment of an
injection device 1
according to the invention. ,
[0042] Figures 2, 3 and 4 show a series of cross-sectional views illustrating
the operation
of device 11 shown by Fig. 1.
[0043] Figures 5 and 6 show exploded cross-sectional views of device 11 from
different
points of view.
[004~~] Figures 7 and 8 show e~~terior views of device 11 from different
points of view.
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[0045] Fig. 9 shows a cross-sectional view of an injection device having a
second
embodiment of ignition means.
[004] Figures 10, 11 and 12 show a series of cross-sectional views
illustrating tile
operation of the device shown by Fig. 9.
[0047] Figures 13 and 14 sh~w exploded cross-sectional views of the device
shown by
Fig. 9 from different points of view.
[004] Fig. 15 shows a cross-sectional view of an injection device having a
third
embodiment of ignition means.
[0049] Figures 16, 17 and 1g show a series of cross-sectional views
illustrating the
operation of the device shown by Fig. 15.
[0050] Figures 19 and 20 show exploded cross-sectional views of the device
shown by
Fig. 15 from different points of view.
[0051] Fig. 21 shows a cross-sectional view of an injection device having a
fourth
embodiment of ignition means.
[0052] Figures 22, 23 and 24 show a sexies of cross-sectional views
illustrating the
operation of the device shown by Fig. 21.
[0053] Figures 25 and 26 show exploded cross-sectional views of the device
shown by
Fig. 21 from different points of view.
[0054] Figures 27 and 2~ show exterior views of device shown by Fig. 21 from
different
points of view.
[0055] Fig. 29 shows a cross-sectional view of an injection device having a
fifth
embodiment of ignition means.
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[0056] Figures 30 and 31 show cross-sectional views illustrating the operation
of the
device shown by Fig. 29.
[005'x] Figures 32 and 33 show e~cploded cross-sectional views of the device
shown by
Fig. 29 from different points of view.
[0058] Figures 34 and 35 show exterior views of device shown by Fig. 29 from
different
points of view.
[0059] Fig. 36 shows a cross-sectional view of an injection device having a
sixth
embodiment of ignition means.
[0060] Figures 37, 38 and 39 show a series of cross-sectional views
illustrating the
operation of the device shown by Fig. 36.
[0061] Figures 40 and 41 show exploded cross-sectional views of the device
shown by Fig.
36 from different points of view.
[0062] Figures 42 and 43 show exterior views of device shown by Fig. 36 from
different
points of view.
[0063] Fig. 44 shows a cross-sectional view of an injection device having a
seventh
embodiment of ignition means.
[0064] Figures 45 and 46 show cross-sectional views illustrating the operation
of the
device shown by Fig. 44.
[0065] Figures 47 and 48 show exploded cross-sectional views of the device
shown by Fig.
44 from different points of view.
[0066] Figures 49 and 50 show exterior views of device shown by Fig. 44 from
different
points of view.
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[0067] Fig. 51 shows a cross-sectional view of an injection device having an
eighth
embodiment of ignition means.
[006] Figures 62, and 53 shove' cross-sectional views illustrating the
operation of the
device shown by Fig. 51.
[0069] Figures 54 and 55 show exploded cross-sectional views of the device
shown by Fig.
51 from different points of view.
[0070] Figures 56 and 57 show exterior views of device shown by Fig. 51 from
different
points of view.
[0071] Fig. 58 shows a cross-sectional view of an injection device having a
ninth
embodiment of ignition means.
[0072] Figures 59, 60 and 61 show cross-sectional views illustrating the
operation of the
device shown by Fig. 58.
[0073] Figures 62 and 63 show exploded cross-sectional views of the device
shown by Fig.
58 from different points of view.
[0074] Fig. 64 shows a cross-sectional view of an injection device having a
breakable
membrane containing burning propellant.
[0075] Fig. 65 shows a cross-sectional view of an injection device having
medication
partly contained in a rigid shell and nozzle, and expelled by a diaphragm.
[0076] Fig. 66 shows a cross-sectional view of an injection device having
medication
contained in a rigid shell and nozzle, and expelled by a piston.
[0077] Fig. 67 shows a cross-sectional view of an injection device having a
modular
pyrotechnic system.
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[0078] Fig. 68 shows a cross-sectional view of the modular pyrotechnic system
of Fig. 67.
[007] Fig. 6~ shows a cross-sectional view of a prior art stab igniti~n
primer.
[000] Fig. 70 shows a cross-sectional view of a stab ignition primer module
incorp~rating
a bistable spring and firing pin.
[0081] Fig. 71 shows a cross-sectional view of an ignition primer module
incorporating a
friction firing pin.
DETAILED DESCRIPTI~N OF PREFERRED EMB~DIMENTS
[0082] Various embodiments of a device according to the invention for
delivering a
needleless hypodermic injection of a liquid medication contained_therein are
described
hereinafter with reference to the accompanying figures. Each of these
embodiments
comprises pyrotechnical means for generating within the device a pressure
necessary
for injecting the medication. For this purpose, the embodiments described
hereinafter
comprise non-electric ignition means utilizing stab primers for igniting a
propellant
contained in the device.
[0083] The terms "free volume" , "total volume" and "surface area" used in the
following
description of preferred embodiments have the following meanings within the
context
of the instant invention:
[0084] The components of an injection device according to the invention are
contained in a
shell which is configured and dimensioned to withstand the injection pressure
generated
within the device by combustion of a propellant. Such a cell is called the
pressurized
shell of the injection device.
[008] The term "free volume" stands for the initial volume within the
pressurized shell
that is neither occupied by solid material such as metal, polycarbonate, or
polyethylene, nor by fluid. Therefore, it is that part of the volume within
the
pressurized shell into which the combustion gases can extend immediately after
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ignition. The "total volume" at the end of the injection is the initial "free
volume" plus
the volume of the liquid ejected from the cartridge. The "surface area" is the
area of
solid materials contacted by the combustion gases.
[006] The above-defined "free volume", "total volume" and "surface area."
affect the
performance of the injection device in the following ways:
[0087] The "free volume" and the mass of propellant determine the maximum
value
reached by the initial injection pressure after ignition. If the "free volume"
is
increased, an increased propellant mass is required to reach a given initial
injection
pressure.
[0088] The pressure drops from the initial injection pressure to the end of
injection
pressure because of the mechanical work done as the gas expands from the "free
volume" to the "total volume" . The pressure also drops because of heat
transfer to the
"surface area".
[0089] The "free volume" and the propellant quantity are adjusted to provide
the required
initial injection pressure and end of injection pressure. As "surface area"
and resulting
heat losses increase, the "free volume" and propellant mass must be increased
to
compensate. Minimization of "surface area" therefore leads to minimum "free
volume"
and propellant mass. Reduction of propellant mass reduces the size and cost of
the
pressure containment structure required for safe operation, and makes single
use
disposable injectors econonucally attractive.
EMBODIMENT 1
[0090] Fig. 1 shows a first embodiment of a device 1 according to the
invention. Device 1
is a cartridge characterized in that the ignition means contained therein
comprise a two-
side-open primer 2 and a firing pin 5 for striking primer 2. Frimer 2 is
positioned
within a propellant chamber 3 that supports the outside diameter of primer 2
and
locates it axially. Firing pin 5 is urged towards primer 2 by compressed
spring 6, and
held in this cocked position by release lever 7 attached to firing pin 5 by
the breakable
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crimp joint 8. Propellant chamber 3 includes a cylindrical bore 9 that holds a
resilient
cup seal 10 adjacent to the primer 2. Cup seal 10 has a central hole 12 large
enough in
diameter that the firax~g pin 5 may pass through and strife the primer 2.
Preferably,
primer 2 contains the full quaaatity of propellant required for the injection.
~ptionally,
additional propellant may be placed in chamber 32.
[0091] Primer 2 is preferably a "green igniter" of the type that avoids
pollution problems
and toxicity issues due to toxic heavy metals contained in "non-green"
igniters.
[0092] An important advantage of the first embodiment of the ignition means is
that it can
be manufactured at low cost for two principal reasons. First, manufacture of
stab
primers 2 uses technology and production capacity established to serve
existing military
and civilian markets. It may be purchased as a sealed, assembled module that
includes
all the required propellant. Second, the mechanical ignition energy
requirement of less
than 10 millijoules results in small, low-cost firing pins 5, springs 6 and
release levers
7. The spring illustrated in Fig. 1 (Associated Spring part number C0180-016-
0440),
for example, has an outside diameter of 4.57 millimeters, a free length of
9.65
millimeters, and wire diameter of 0.4 millimeters. It stores 11.9 millijoules
of
mechanical energy.
[0093] Ignition of primer 2 preferably produces the required hot gas on its
own.
~ptionally, it lights additional propellant contained in the chamber 32 to
generate
additional hot gas.
[0094] Additional propellant optionally contained within device 1 is, for
example, a fine
grain nitrocellulose based composition or another nitrocellulose based
composition, or
another propellant composition having similar properties or a mixture of
propellant
compositions.
[0095] Two end open stab primer 2 is preferably closed at each end by moisture
seals that
open at low pressure and exclude contact of the primer material with water
vapor prior
to use of the device.
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[0096] When the pressure reaches a predetermined level, the burst diaphragm
opens and
the pressure generated by combustion of the primer and propellant causes
ejection of
the medication out of the device for performing an injection.
[009'] Injection device 1 described above can have different structures, and
the illustrated
structure is only an example.
[009] Fig. 1 shows a cross-sectional view of a structure of device 1 designed
as a single
use device, that is a device which is used only once and discarded after use.
[0099] Injection device 1 shown by Fig. 1 comprises a housing consisting of a
first housing
part 20, e.g. an aluminum shell, and a second housing part 21, made of, for
example, a
polycarbonate. Housing parts 20 and 21 have threads which match with each
other and
are thus be connected with each other by a screw connection 30.
[0100] In a preferred embodiment, the housing of device 1 is so configured and
dimensioned that as a whole it is adapted to withstand an internal pressure
which is
higher than the normal injection pressure without yielding.
[0101] In a preferred embodiment, both parts 20 and 21 of the housing of
device 11 are
made of suitable plastic materials, e. g. , from commercially available
polyesters or
polycarbonates taking in particular into account the mechanical properties the
housing
should have.
[0102] The interior of the housing of device 11'comprises a first chamber 31
and a second
chamber 32, which are defined for instance by respective cavities of a support
member
28.
[0103] A medication unit 13 comprising nozzle 15 and medication container 12
formed by
deformable wall 14 is arranged within first chamber 31. A volume of liquid to
be
injected is stored in medication unit 13. In preferred embodiments, the amount
of this
volume is in a range from about 50 to about 1000 microliters. Specific
examples of this
amount are, for example, 200 or 500 microliters.
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[0104] Medication unit 13 is a sealed medication module which comprises a
nozzle body
15 and a flexible container wall 14~ that hermetically encloses a portion of
the nozzle
and forms a reservoir 12 for a. liquid medication stored in sealed medication
unit 13.
5~a11 14 is deformable aaad coll~.psible.
[0105] Medication unit 13 thus comprises a first region and a second region
that are in
liquid communication with each other. The first region is deformable and
comprises the
reservoir enclosed by flexible wall 14. The second region of medication unit
13
comprises nozzle 15, which has a fluid channel 16 that ends in an orifice 17,
which
serves as a liquid jet outlet through which liquid to be injected is ejected
when an
injection is performed with injector module 11. Medication unit 13 is made of
one or
more suitable construction materials, e.g., polyethylene and polypropylene,
which are
suitable for storing medications including sensitive protein drugs.
[0106] A part of container wall 14 forms a break-off protective cap 19 that
covers a jet
orifice 17 of nozzle body 15. Cap 19 is removed by the user just prior to use
of
injector module 11.
[0107] First chamber 31 comprises two zones, a first zone 33 which contains
medication
unit 13 and a second zone 34 which is located between medication unit and
second
chamber 32. First chamber 31 is in communication with second chamber 32 so
that
upon ignition of stab primer 2 located within second chamber 32, gas thereby
generated
expands into second zone 34 of first chamber 31, exerts pressure on and
deforms
deformable wall 14 of the first region of medication unit 13 and thereby
causes ejection
of the liquid medication through channel 16 and orifice 17.
7
[0108] In a preferred embodiment, a deformablelelastic barrier 18 divides the
first zone 33
from the second zone 34. The elastic barrier is made of materials like, for
example,
silicon rubber, and can be reinforced with materials like, for example, woven
aramid
fibers.
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[0109] In a preferred embodiment the free volume comprised between medication
unit 13
and the wall of support member 28 is much smaller than the volume available
for
containing propellant within the device.
[0110] Figures 2 through 4 illustrate the operating sequence of needleless
injection device
1.
[0111] Fig. 2 shows needleless injection device 1 prior to the injection. The
removable cap
19 is broken off to uncover the sterile injection nozzle 17, and the nozzle is
pressed
against the patient's skin at the injection site.
[0112] Fig. 3 shows needleless injection device 1 at the instant of ignition.
As a result of
pushing the release lever 7 to one side, the breakable crimp joint 8 separates
and
releases firing pin 5. The compressed spring 6 accelerates firing pin 5 so
that its tip
passes through hole 11 in cup seal 10 and strikes and ignites primer 2. The
hot
products of combustion of primer 2 ignite any optional propellant contained in
chamber
32. The release lever 7 may be pushed directly by the user or indirectly
through a
mechanism that is part of an application device (not shown).
[0113] Fig. 4 shows needleless injection device 1 an instant following
ignition. Hot gas
flows from the front opening of the two opening stab primer 2 into chamber 31
through
chamber 32. Chamber 32 may contain additional propellant of the same or a
different
type that burns and adds to the hot gas. The hot gas in chamber 31 applies
pressure to
the liquid medication unit 12 through the flexible wall 14 of the medication
unit 13 and
through the deformable elastic barrier 18. This pressure forces the liquid
medication
unit 12 through fluid channel 16 and out the injection nozzle 17, which forms
the skin-
penetrating jet. The pressure rises to a maximum initially, and drops to lower
values as
the injection proceeds to completion. At the same time, hot gas flows from the
rear
opening of the two opening stab primer. 2 and forces back the cup seal 10 and
firing pin
through the bore 9 until the firing pin contacts and seals against seat 22.
The
combined effects of the cup seal 10 and the firing pin 5 are to contain the
hot gas in
free volume 23, and prevent unwanted flow into the volume surrounding the
spring 6
and the annular space between the firing pin 5 and the second housing part 21.
Such
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unwanted flow would result in loss of efficiency through an increase in dead
volume,
heat losses to solid surfaces, and eternal leakage.
[Oll~~] Figures 5 and 6 show eaaploded cross-sectional views of components of
device 1
shown by Figures 1 through 4 from different points of view. Figures 7 and ~
show
e~~ternal views of device 1 shown by Figures 1 through 6 from different points
of view.
[0115] Figures 9 to 71 show seven additional embodiments of stab primer
ignition means
suitable for use as part of an injection device having a structure similar to
the structure
of the above described injection device 1 in Fig. 1. The descriptions of the
additional
embodiments include only the new elements, and do not repeat the description
of the
complete device.
[0116] In particular, an advantage of the above-described embodiment 1 is that
there is no
contact between the hot gas generated in the propellant chamber and the spring
used for
driving the firing pin. Therefore, there is no loss of energy that would be
caused by
such a contact. Another advantage of embodiment 1 is that the structure of the
device
ensures a good sealing of the propellant chamber and this sealing is assisted
by the
pressure generated within the propellant chamber. Therefore, there is no loss
of
pressure built up in the propellant chamber that would be due to lack of a
good sealing
thereof. Thus, the whole pressure generated within the propellant chamber is
available
for being effectively used as injection pressure.
EMB~IDIMENT 2
[0117] Fig. 9 shows a sectional view of an injection device 47 having a
similar structure as
injection device 1 shown in Fig. 1, but wherein one side open stab primer 45
is
utilised.
[Oll~] ~ne side, open stab primer 45 is slidably mounted in bore 46 of the
propellant
chamber 41, and is oriented such that the open side faces the sharp point of
stab pin 42.
Stab pin 42 is concentric with primer 45, and is attached to support bridge 43
that
crosses chamber 32 of propellant chamber 41. Flow passages 44 on each side of
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support bridge 43 connect the open side of primer 45 to chamber 32 and chamber
31.
Tmpact plunger 40 is positioned adjacent to the closed side of the primer 45,
and
slideably held in hole 3~ in second housing part 37. hnpact plunger 40 is
urged towards
primer 45 by compressed spring ~, and held ia~ this cocked position by release
lever 7
attached to impact plunger 40 by the breakable crimp joint 3. Preferably,
prixr~er 45
contains the full quantity of propellant required for the injection.
~ptionally, additional
propellant may be placed in chamber 32.
[0119] Primer 45 is preferably a "green'igniter" of the type that avoids
pollution problems
and toxicity issues due to toxic heavy metals contained in "non-green"
igniters.
[0120] Figures 10 through 12 illustrate the operating sequence of needleless
injection
device 47.
[0121] Fig. 10 shows needleless injection device 47 prior to the injection.
The removable
cap 19 is broken off to uncover the sterile injection nozzle 17, and the
nozzle is pressed
against the patient's skin at the injection site.
[0122] Fig. 11 shows needleless injection device 47 at the instant of
ignition. As a result of
pushing the release lever 7 to one side, the breakable crimp joint ~ separates
and
releases impact plunger 40. The compressed spring 6 accelerates impact plunger
40 so
that it contacts and accelerates primer 45 toward stab pin 42, such that stab
pin 42
penetrates and ignites primer 45. The hot products of combustion of primer 45
pass
around support bridge 43 through flow passages 44, and ignite any optional
propellant
contained in chamber 32. The release lever ,7 may be pushed directly by the
user or
indirectly through a mechanism that is part of an application device (not
shown).
[0123] Fig. 11 shows needleless injection device 47 an instant following
ignition. Hot gas
flows from the front opening of the one opening stab primer 45 into chamber 31
through chamber 32 and flow passages 44. Chamber 32 may contain additional
propellant of the same or a different type that burns arid adds to the hot
gas. The hot
gas in chamber 31 applies pressure to the liquid medication unit 12 through
the flexible
wall 14 of the medication unit 13 and through the deformable elastic barrier 1
~ . This
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pressure forces the liquid medication unit 12 through fluid channel 16 and out
the
injection nobble 17 which forms the skin-penetrating jet. The pressure rises
to a
maximum initially, and drops to lover values as the injection proceeds to
completion.
At the same tune, hot gas pressure on the empty pri~xaer shell 4~3 of the one
opening
stab primer 4~ forces back the primer shell ~.~ and impact plunger 40 through
the bore
46 until the impact plunger contacts seat 39. eaas pressure expands the primer
shell 4~
so that it seals against bore 46. The combined effects of the primer shell 4~
and the
impact plunger 40 are to contain the hot gas in free volume 49, and prevent
unwanted
flow into the volume surrounding the spring 6 and the annular space between
the
impact plunger 40 and the second housing part 37. Such unwanted flow would
result in
loss of efficiency through an increase in dead volume, heat losses to solid
surfaces, and
external leakage.
[0124] Figures 13 and 14 show exploded cross-sectional views of components of
device 47
shown by Figures 9 through 12 from different points of view.
[0125] An advantage of the above-described embodiment 2 over embodiment 1 is
that the
shell of the stab primer effectively seals the propellant chamber and no
additional
sealing means is required for sealing this chamber. Thus, embodiment 2 and the
manufacturing process for making it are cheaper. Moreover, due to the good
sealing of
the propellant chamber ensured by the shell of the stab primer, there is no
loss of
pressure built up in the propellant clianiber that would be due to lack of a
good sealing
thereof. Thus, the whole pressure generated within the propellant chamber is
available
for being effectively used as injection pressure. As in the case of embodiment
1, there
is also no contact between the hot gas generated in the propellant chamber and
the
spring used for driving the firing pin. Therefore, there is no loss of energy
that would
be caused by such a contact.
EMB~DIMENT 3
[0126] Fig. 15 shows a sectional view of an injection device 50 having a
similar structure
and ignition means as injection device 47 shown in Fig. 9, but wherein a
different
impact plunger release mechanism is. employed.
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[0127] Impact plunger 40 in Fig. 9 is replaced by impact plunger 51 having a
tapered
section 52, a hook 53, and a release lever 54. Kook 53 engages the second
housing part
58 when impact plunger 51 is pulled back to compress spring 6 and pushed to
one side
in hole 59. This holds impact plunger ~1 in the cocked position, and spring 6
tilts to
accommodate the resulting angularity. cylindrical guide sleeve 55 is
preferably formed
as part of second housing part 58, and encircles release lever 54. Release
latch 56 is a
cylindrical rod with a conical cavity 57 in one end. Release latch 56 is a
sliding fit
within guide sleeve 55. Guide sleeve 55 also protects release lever 54 from
accidental
contact and release during production handling. Release latch 56 is preferably
part of a
separate application device (not shown), and not part of injection device 50.
[0128] Fig. 16 shows needleless injection device 50 prior to the injection.
The removable
cap 19 is broken off to uncover the sterile injection nozzle 17, and the
nozzle is pressed
against the patient's skin at the injection site.
[0129] Fig. 17 shows needleless injection device 50 at the instant of
ignition. As a result of
pushing release latch 56 into guide sleeve 55, the conical cavity 57 contacts
the release
lever 54 and forces it to center. This action disengages hook 53 from second
housing
part 58, and releases impact plunger 51. As described for injection device 47
shown in
Fig. 9, the ignition process proceeds.
[0130] Fig. 18 shows needleless injection device 50 an instant following
ignition. As
described for injection device 47 shown in Fig. 9, the propellant combustion
and
injection process proceeds. At the same time, hot gas pressure on the empty
primer
shell 48 of the one opening stab primer 45 forces back the primer shell 48 and
impact
plunger 51 through the bore 46 until the impact plunger contacts seat 66. Gas
pressure
expands the primer shell 48 so that it seals against bore 60. The combined
effects of the
primer shell 48 and the impact plunger 51 are to contain the hot gas in free
volume 49
and prevent unwanted flow into the volume surrounding the spring 6 and the
annular
space between the impact plunger 51 and the second housing part 58. Such
unwanted
flow would result in loss of efficiency through an increase in dead volume,
heat losses
to solid surfaces, and e~~ternal leakage.
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[0131] Figures 19 and 20 show exploded cross-sectional views of components of
device 50
shown by Figures 15 through 18 from different points of view.
[~132] An advantage of the above-described embodiment 3 over embodiment 2 is
that the
release motion, i.e., the motion of release latch 56, is in jet direction, and
this makes
use of the injection device easier than when the release motion is in other
directions.
~I~BO~4
[0133] Fig. 21 shows a sectional view of an injection device 60 having a
similar structure
as injection device 1 shown in Fig. l, but wherein firing pin 5 and spring 6
in device 1
are replaced by firing pin 61 and bistable disk spring 62.
[0134] The ignition means comprises two side open primer 2 positioned within a
propellant
chamber 64 that supports the outside diameter of primer 2 and locates it
axially. Firing
pin 61 is attached to the center of bistable disk spring 62, such that the
sharp end faces
the center of primer 2. Bistable disk spring 62 is supported at its outer edge
65 by an
annular pivot formed by opposing surfaces of propellant chamber 64 and second
housing part 68. It is shown in a first stable position in which it is concave
away from
primer 2, and firing pin 61 does not contact primer 2. Actuation screw 63 is
threaded
into hole 66 in second housing part 68, and is arranged such that it may be
turned to
push the center of bistable disk spring 62 and firing pin 61 toward primer 2.
Preferably, primer 2 contains the full quantity of propellant required for the
injection.
Optionally, additional propellant rnay be placed in chamber 32.
[0135] Figures 22 through 24 illustrate the operating sequence of needleless
injection
device 60.
[0136] Fig. 22 shows needleless injection device 60 prior to the injection.
The removable
cap 19 is broken off to uncover the sterile injection nozzle 17, and the
nozzle is pressed
against the patient's skin at the injection site.
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[0137] Fig. 23 shows needleless injection device 60 at the instant of
ignition. As a result of
turning the actuation screw 63, the bistable disk spring 62 and firing pin 61
are pushed
toward primer 2. ~2t a transition point, the bistable disk spring 62 snaps to
a second
stable position causing the firing pin 61 to penetrate and ignite primer 2.
The hot
products of combustion of primer 2 ignite any optional propellant contained h1
chamber
32. The actuation screw 63 may be turned directly by the user or indirectly
through a
mechanism that is part of an application device (not shown).
[0138] Fig. 24 shows needleless injection device 60 an instant following
ignition. As
described for injection device 1 shown in Fig. 1, the propellant combustion
and
injection process proceeds. At the same time, hot gas flows from the rear
opening of
the two opening stab primer 2 and forces back the bistable disk spring 62 and
firing pin
61 against the actuation screw 63 at the center and the second housing part 6~
at the
outer edge. This forms a barrier and~seal that blocks hot gas flow to the
vicinity of the
actuation screw 63.
[0139] Figures 25 and 26 show exploded cross-sectional views of components of
device 60
shown by Figures 21 through 24 from different points of view. Figures 27 and
28 show
external views of device 60 shown by Figures 21 through 26 from different
points of
view.
[0140] The above-described embodiment 4 offers the following advantages:
- safety of operation is improved by the fact that 53 blocks the rear of
device 60 and
that the device does not have any fast moving parts outside the device,
- the structure of the device is very compact, and this makes possible to
obtain a high
gas pressure,
- after ignition of the propellant, there is a very limited increase of the
volume available
for the gas generated within the device,
- only a relatively small surface is in contact with combustion gases, i.e.
heat loss is
very low and thereby loss of injection pressure generated by combustion of the
propellant is also very low,
- disk spring 62 can be a non-metallic one, e.g. ~. material with a low
elasticity
modulus, and
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- since spring 62 serves as seal and provides a good sealing of the propellant
chamber,
no other sealing means is required.
~ rI~~I1~I~~1~~T'T ~
[0141] Fig. 29 shows a sectional view of an injection device 70 having a
similar structure
as injection device 60 shown in Fig. 21, but wherein a different spring and
release
mechanism is employed.
[0142] Bistable disk spring 62 in device 60 that provides a gas barrier
function is replaced
in injection device 70 by bistable disk spring 71, that includes vent holes 72
that
equalizes pressure on both sides of the disk spring. Actuation screw 63 .in
device 60 is
replaced by small diameter actuation push pin 73 with enlarged diameter head
78 on
one end. Rubber seal 74 is added between push pin 73 and second housing part
75 to
block gas flow out of device 70. The ignition means comprises two side open
primer 2
positioned within a propellant chamber 64 that supports the outside diameter
of primer
2 and locates it axially. Firing pin 61 is attached to the center of bistable
disk spring
71, such that the sharp end faces the center of primer 2. Bistable disk spring
71 is
supported at its outer edge 76 by an annular pivot formed by opposing surfaces
of
propellant chamber 64 and rear housing 75. It is shown in a first stable
position in
which it is concave away from primer 2, and firing pin 61 does not contact
primer 2.
Actuation pin 73 slides into hole 77 in rear housing 75, and is arranged such
that it
transfers an externally applied force to push the center of bistable disk
spring 71 and
firing pin 61 toward primer 2. Enlarged diameter head 78 is on the end of the
pin
inside rear housing 75.
[0143] Figures 30 and 31 illustrate the operating sequence of needleless
injection device
70.
[0144] Fig. 30 shows needleless injection device 70 prior to the injection.
The removable
cap 19 is broken off to uncover the sterile injection nozzle 17, and the
nozzle is pressed
against the patient's skin at the injection site.
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[01451 Fig. 31 shows needleless injection device 70 during and after the
instant of ignition.
As a result of pushing the actuation push pin 73, the bistable disk spring 71
and firing
pin 61 are pushed toward primer 2. At a transition point, the bistable disk
spring 71
snaps t~ a second stable position causing the fixing pin 61 to penetrate and
ignite primer
2. 'phe hot products of combustion of primer 2 ignite any optional propellant
contained
in chamber 32. Actuation push pin 71 may be pushed directly by the user or
indirectly
through a mechanism that is part of an application device (not shown). As
described for
injection device 60 shown in Fig. 21, the propellant combustion and injection
process
proceeds. At the same time, hot gas flows from the rear opening of two opening
stab
primer 2 and through vent holes 72 in bistable disk spring 71. This gas
pressure acts on
actuation push pin 73, and tends to push it out of the hole 77 in rear housing
75.
Because of the small diameter of actuation push pin 73, this force is small
and is
resisted by the external force applied by the user or the actuation device.
Head 7~ on
actuation push pin 73 prevents its ejection in the event that the external
force is lower
than the pressure force. Rubber seal 74 prevents gas flow through the annular
clearance
between actuation push pin 73 and~rear housing 75.
[0146] Figures 32 and 33 show exploded cross-sectional views of components of
device 70
shown by Figures 29 through 31 from different points of view. Figures 34 and
35 show
external views of device 70 shown by Figures 29 through 33 from different
points of
view.
[0147] The above described embodiment 5 offers the following advantages:
- the actuation motion is in jet direction,
- actuation of the ignition means is effected by a linear push motion and
there is a
natural release point determined by the properties of disk spring 71,
- the structure of the device is very compact and this makes possible to
obtain a high
gas pressure,
- after ignition of the propellant there is no increase of the volume
available for the gas
generated within the device, and
- disk spring 71 can be a non-metallic one, e.g. a material with a low
elasticity
modulus .
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EMBODIIVVIEENT 6
[01411] Fig. 3~a shows a sectional view of an injection device 80 having a
similar structure
as injection device 1 shown in Fig. 1'9 but wherein firing pin 5 and cup seal
10 in
device 1 are replaced by firing pin 81 and seal bushing 82,9 with the
objective of
minimizing the free volume 94 and surface area associated with the firing pin
mechanism.
[0149] The ignition means comprises two side open primer 2 positioned within a
propellant
chamber 83 that supports the outside diameter of primer 2 and locates it
axially at the
front end 89. Seal bushing 82 contains and locates primer 2 at the rear end
90, and has
clearance hole 84. Firing pin 81 includes shoulder 86, flange 93 and break
region 87.
Break region 87 consists, for example, of a groove that locally weakens firing
pin 81.
Firing pin 81 is urged towards primer 2 by compressed spring 91 that bears
against
spring retainer washer 85 that in turn bears on shoulder 86. It is held in
this cocked
position by release lever 88 attached~to firing pin 81 by connection joint 92.
Firing pin
81 passes through clearance hole 84 in seal bushing 82. Preferably, primer 2
contains
the full quantity of propellant required for the injection. Optionally,
additional
propellant may be placed in chamber 32.
[0150] Figures 37 through 39 illustrate the operating sequence of needleless
injection
device 80.
[0151] Fig. 37 shows needleless injection device 80 prior to the injection.
The removable
cap 19 is broken off to uncover the sterile injection nozzle 17, and the
nozzle is pressed
against the patient's skin at the injection site.
[0152] Fig. 38 shows needleless injection device 80 at the instant of
ignition. As a result of
pushing release lever 88 to one side, break region 87 in firing pin 81
separates and
releases firing pin 81. The compressed spring 91 accelerates firing pin 81 so
that it
slides though clearance hole 84 in seal bushing 82 and strikes and ignites
primer 2. The
hot products of combustion of primer 2 ignite any optional propellant
contained in
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chamber 32. The release lever 88 may be pushed directly by the user or
indirectly
through a mechanism that is part of an application device (not shown).
[01~~] Fig. 39 shows needleless injection device 80 an instant following
ignition. As
described for injection device 1 shown in Fig. 1, the propellant combustion
and
injection process proceeds. lit the same time, hot gas flows from the rear
opening of
two opening stab primer 2 and forces back firing pin 81 through clearance hole
84 until
flange 93 contacts seal bushing 82 and forms seal joint 95. The effect is to
contain the
hot gas in free volume 94, and prevent unwanted flow into the volume
surrounding
spring 91 and the annular space between the firing pin 81 and the second
housing part
96. Such unwanted flow would result in loss of efficiency through an increase
in dead
volume, heat losses to solid surfaces, and external leakage. Embodiment 6 is
notable in
that free volume 94 may be very small.
[0154] Figures 40 and 41 show exploded cross-sectional views of components of
device 80
shown by Figures 36 through 39 from different points of view. Figures 42 and
43 show
external views of device 80 shown by Figures 36 through 41 from different
points of
view.
[0155] The above described embodiment 6 offers the following advantages:
- the volume available for gas expansion behind the igniter is minimized,
- only a relatively small surface is in contact with combustion gases, i.e.,
heat loss is
very low and thereby loss of injection pressure generated by combustion of the
propellant is also very low, and
- the structure of the device ensures a good sealing of the propellant chamber
and this
sealing is assisted by the pressure generated within the propellant chamber.
EMB~DIMENT 7
[0156] Fig. 44 shows a sectional view of an injection device 100 having a
similar structure
as injection device 1 shown in Fig. 1, but wherein firing pin 101 and spring
102 and
the associated release mechanism are contained within free volume 103 that is
filled by
hot gas
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(0157] The ignition means comprises two side open primer 2 positioned within a
propellant
chamber 104 that supports the outside diameter of primer 2 and locates it
axially at the
front end 89. propellant chamber 104 also incorporates support shoulders 111
and
release grooves 112. Firing pin 101 includes flange 105 with latch ears 106,
and a twist
shaft 107 that e~ctends through shaft seal 108 and hole 110 in second housing
part 109.
Twist shaft 107 provides a means of rotating firing pin 101 by a torque
applied from
outside injection device 100. Compressed spring 102 holds shaft seal 10~ in
contact
with second housing part 109. Firing pin 101 is urged towards primer 2 by
compressed
spring 102 that bears against flange 105. In a first rotational position,
firing pin 101 is
held in this cocked position by the engagement of latch ears 106 with support
shoulders
111. In a second rotational position, latch ears 106 disengage from support
shoulders
111 and align with release grooves 112, freeing firing pin 101 to move axially
and
make contact with primer 2. Preferably, primer 2 contains the full quantity of
propellant required for the injection. Optionally, additional propellant may
be placed in
chamber 32.
[0158] Figures 45 and 46 illustrate the operating sequence of needleless
injection device
100.
[0159] Fig. 45 shows needleless injection device 100 prior to the injection.
The removable
cap 19 is broken off to uncover the sterile injection nozzle 17, and the
nozzle is pressed
against the patient's skin at the injection site.
[0160] Fig. 46 shows needleless injection device 100 during and after the
instant of
ignition. As a result of turning twist shaft 107, firing pin 101 shifts from a
first
rotational position in which it is held in a cocked position by the engagement
of latch
ears 106 with support shoulders 111, and reaches a second rotational position
wherein
latch ears 106 disengage from support shoulders 111 and align with release
grooves
112. Compressed spring 102 is then free to accelerate firing pin 101 so that
it strikes
and ignites primer 2. The hot products of combustion of primer 2 ignite any
optional
propellant contained in chamber 32. As described for injection device 60 shown
in Fig.
21, the propellant combustion and injection process proceeds. At the same
time, hot
gas flows from the rear opening 90 of two opening stab primer 2 and into free
volume
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103. This gas pressure acts on twist shaft 107, and tends to push it out
through hole
110 in second housing part 109. Because of the small diameter of twist shaft
107, this
force is small and is resisted by the residual force of spring 102 and
external force
applied by the user or the ~.ctuation device. Flange 105 on firing pan 101
prevea~ts its
ejection in the event that the resisting force is lower than the pressure
force. Shaft seal
108 prevents gas flow through the annular clearance between twist shaft 107
and
second housing part 109. Twist shaft 107 may be turned directly by the user or
indirectly through a mechanism that is part of an application device (not
shown).
[0161] Figures 47 and 48 show exploded cross-sectional views of components of
device
100 shown by Figures 44 through 46 from different points of view. Figures 49
and 50
show external views of device 100 shown by Figures 44 through 48 from
different
points of view.
[0162] The above-described embodiment 7 offers the advantages of actuation
obtained by a
rotary motion and when the actuation means reaches a defined angular position.
EMBODIMENT 8
[0163] Fig. 51 shows a sectional view of an injection device 120 having a
similar structure
and firing pin mechanism as injection device 100 shown in Fig. 44, but wherein
firing
pin 121 and twist shaft 122 are separate parts, not an integral component,
with the
result that twist shaft 122 does not move axially with the firing pin, and
undergoes
rotational motion only.
[0164] The ignition means comprises two side open primer 2 positioned within a
propellant
chamber 123 that supports the outside diameter of primer 2 and locates it
axially at the
front end 89. Propellant chamber 123 also incorporates support shoulders 111
and
release grooves 112. Firing pin 121 includes flange 124 with latch ears 125,
and a
clutch slot 126. Twist shaft 122 includes clutch blade 129 and seal flange
127, and
extends through hole 128 in second housing part 130. Clutch blade 129 on twist
shaft
122 engages clutch slot 126 in firing pin 121, such that firing pin 121
rotates when
twist shaft 122 is rotated by a torque applied from outside injection device
120. Firing
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pin 121 is urged towards primer 2 by compressed spring 131 that bears against
flange
124. In a first rotational position firing pin 121 is held in this cocked
position by the
engagement of latch ears 124 with support shoulders 111. Tn a second
rotational
position latch eaxs 124 disengage from support shoulders 111 and align with
release
grooves 112, freeing firing pin 121 to move axially and make contact with
primer 2.
Clutch slot 126 in firing pin 121 slides off clutch blade 129 of twist shaft
122 as firing
pin 121 moves axially toward primer 2 and twist shaft 122 remains motionless.
Preferably, primer 2 contains the full quantity of propellant required for the
injection.
~ptionally, additional propellant may be placed in chamber 32.
[0165] Figures 52 and 53 illustrate the operating sequence of needleless
injection device
120.
[0166] Fig. 52 shows needleless injection device 120 prior to the injection.
The removable
cap 19 is broken off to uncover the sterile injection nozzle 17, and the
nozzle is pressed
against the patient's skin at the injection site.
[0167] Fig. 53 shows needleless injection device 120 during and after the
instant of
ignition. As a result of turning twist shaft 122 and that is rotationally
coupled to firing
pin 121, firing pin 121 shifts from a first rotational position in which it is
held in a
cocked position by the engagement of latch ears 125 with support shoulders
111, and
reaches a second rotational position wherein latch ears 125 disengage from
support
shoulders 111 and align with release grooves 112. Compressed spring 131 is
then free
to accelerate ftring pin 121 so that it strikes and ignites primer 2. The hot
products of
combustion of primer 2 ignite any optional propellant contained in chamber 32.
As
described for injection device 60 shown in Fig. 21, the propellant combustion
and
injection process proceeds. At the same time, hot gas flows from the rear
opening 90 of
two opening stab primer 2 and into free volume 132. This gas pressure acts on
twist
shaft 122, and pushes seal flange 127 against second housing part 130 to
effect a seal
that prevents gas flow through the annular clearance between twist shaft 122
and
second housing part 130. Twist shaft 122 may be turned directly by the user or
indirectly through a mechanism that is part of an application device (not
shown).
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[0168] Figures 54 and 55 show exploded cross-sectional views of components of
device
120 as shown by Figures 51 through 53 from different points of view. Figures
56 and
57 show external views of device 120 as shown by Figures 51 through 55 from
different points of view.
[0169] The above described embodiment 8 offers the following advantages:
- there is no backward motion of the'actuating shaft and,
- there is a good sealing effect of the propellant chamber at the clutch and
this effect is
assisted by the pressure generated within the propellant chamber.
EMB~DIMENT 9
[0170] Fig. 5~ shows a sectional view of an injection device 200 having a
similar structure
as injection device 1 shown in Fig. 1, but wherein firing pin 5 and cup seal
10 in
device 1 are replaced by firing pin.201 and seal 207, the spring and release
mechanism
are removed from the device, and an externally supplied actuation impact
drives firing
pin 201 into two side open primer 2.
[0171] The ignition means comprises two side open primer 2 positioned within a
propellant
chamber 202 that supports the outside diameter of primer 2 and locates it
axially at the
front end 89. Firing pin 201 extends outside second housing 204, and includes
ratchet
grooves 203. Elastic ratchet fingers 206 engage ratchet grooves 203. Firing
pin 201 is
free to slide toward primer 2, but is prevented from sliding in the opposite
direction by
the engagement of ratchet fingers 206 with ratchet grooves 203. Annular volume
212,
within second housing 204, surrounds firing pin 201 and ratchet fingers 206.
Seal 207
surrounds firing pin 201, and blocks gas flow from free volume 210 to
annular,volume
212. Preferably, primer 2 contains the full quantity of propellant required
for the
injection. ~ptionally, additional propellant may be placed in chamber 32.
[0172] Figures 59 through 61 illustrate the operating sequence of needleless
injection
device 200.
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[Q173] Fig. 59 shows needleless injection device 200 prior to the injection.
The removable
cap 19 is broken off to uncover the sterile injection nobble 17, and the
nozzle is pressed
against the patient's skin at the injection site.
[017~~] Fig. 60 shows needleless injection device 200 at the instant of
ignition. An external
impact motion 211 accelerates firing pin 201 so that it slides though seal 207
and
ratchet fingers 206, and strikes and ignites primer 2. The hot products of
combustion of
primer 2 ignite any optional propellant contained in chamber 32. The external
impact
motion 211 may be generated by a known mechanism such as a spring and plunger
(not
shown).
[0175] Fig. 61 shows needleless injection device 200 an instant following
ignition. As
described for injection device 1 shown in Fig. 1, the propellant combustion
and
injection process proceeds. At the same time, hot gas flows from the rear
opening of
two opening stab primer 2 and forces back firing pin 201 through seal 207
until ratchet
fingers 206 engage ratchet grooves 203 and stop the motion. The effect is to
contain
the hot gas in free volume 210, and prevent unwanted flow into annular volume
212.
Such unwanted flow would result in loss of efficiency through an increase in
dead
volume, heat losses to solid surfaces, and external leakage. Embodinnent 9 is
notable in
that free volume 210 may be very small.
[0176] Figures 62 and 63 show exploded cross-sectional views of components of
device
200 shown by Figures 5~ through 61 from different points of view.
[0177] The above described embodiment 9 offers the following advantages:
- since the device does not include any spring for driving the firing pin,
there is no
contact between the hot gas generated in the propellant chamber and such a
spring, and
there is no loss of energy that would be caused by such a contact,
- only a small volume is available for the expansion of gases generated within
the
device, and
- only a relatively small surface is in'contact with combustion gases, i.e.,
heat loss is
very low and thereby loss of injection pressure generated by combustion of the
propellant is also very low.
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ASPECTS COMMON TO THE PRECEDING EMBODIMENTS
[0178] The ignition means described in detail for each of the above
embodiments 1 to 9 is
suitable for bei~ag used with any of the injection device stTUCtures described
hereinafter
with reference to Figures 64 to 68.
[0179] Fig. 64 shows a sectional view of an injection device 220 having a
similar structure
and function as injection device 1 shown in Fig. 1, but wherein a breakable
membrane
221 separates second chamber 32 from 34, the second zone of first chamber 31.
After
ignition, breakable membrane 221 confines the gas in second chamber 32 up to
predetermined pressure to facilitate combustion, and then bursts to release
the gas to
carry out the injection. The breakable membrane principle illustrated in
injection device
200 is applicable to the ignition and gas generation means described above
with
reference to Figures 1 to 63.
[0180] Fig. 65 shows a sectional view of an injection device 230 having
similar ignition
and gas generation means as injection device 1 shown in Fig. 1, but wherein
nozzle
body 231 connects to rigid housing 232 to form a shell 246 enclosing volume
233, and
further including a first deformable diaphragm 234 which together with a
cavity 235 of
nozzle body 231 forms a medication chamber 236 suitable for receiving a
predetermined amount of a medication 237, and a second deformable diaphragm
238 a
portion of which extends around a portion of first deformable diaphragm 234.
Second
deformable diaphragm 238 and housing 232 form together a chamber 239 that
contains
a propellant and ignition means 240. Nozzle body 231 has a channel 241 and an
orifice
242 at its outer end for ejecting medication 237 out of chamber 236 when a gas
pressure generated by propellant and ignition means 240 is applied to second
deformable diaphragm 238 and thereby to first deformable diaphragm 234. Vents
243
connect the space 244 between second deformable diaphragm 238 and first
deformable
diaphragm 234 to the outside of shell 246, such that inadvertent gas leakage
through
second deformable diaphragm 238 is removed to protect the integrity of first
deformable diaphragm 234 and medication 237. Second deformable diaphragm 238
and
vents 243 are an optional security measure, and injection device 230 will
function with
first deformable diaphragm 234 alone. Propellant and ignition means 240 may
comprise
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any of the ignition and gas generation means described above with reference to
Figures
1 to 63.
[0~.~1] F'ig. 66 shows a sectional view of an i~ajection device 2~0 having
similar ignition
and gas generation means as injection device 1 shown in Fig. 1, but wherein a
rigid
medication container 251 having a medication zone 252 for receiving liquid
medication
253 defined by a cylindrical bore 256, a nozzle end 254,. and a medication
piston 262
slidably arranged within cylindrical bore 256. An outlet orifice 255 is in
fluitlic
communication with medication zone 252. A rigid housing 257 connects to
medication
container 251, and contains a cylindrical bore 258 with a drive piston 259
slidably
arranged within and aligned with and contacting medication piston 262, such
that
motion of drive piston 259 moves medication piston 262 a substantially equal
distance.
Rigid housing 257 and drive piston 259 together form a propellant zone 260
containing
a propellant and ignition means 261, so that upon actuation of propellant and
ignition
means 261, gas pressure generated by combustion of the propellant causes
displacement
of drive piston 259, and thereby medication piston 262, which then exerts
pressure on
liquid medication 253 and ejects it through the outlet orifice 255 of nozzle
end 254.
Propellant and ignition means 261 may be comprise any of the ignition and gas
generation means described above with reference to Figures 1 to 63.
[0182] Fig. 67 shows a sectional view of an injection device 270 having
similax ignition
and gas generation means as injection device 1 shown in Fig. 1, but wherein
two-side-
open primer 2, firing pin 5, propellant chamber 3, spring 6, release lever 7
and cup
seal 10 are combined with a sub-housing 272 by means of a connection 273 to
form a
separable pyrotechnic module 271 containing gas generation and ignition
functions.
Module 271 is shown separately in Fig. 68.~Functionally, injection device 270
is the
same as injection device 1, and the advantage is improved manufacturing
logistics.
Pyrotechnic module 271 may be manufactured, inspected, stored, and transported
separately from the other parts of injection device 270, and added in final
assembly.
The modular principle illustrated in injection device 270 is applicable to the
ignition
and gas generation means described above with reference to Figures 1 to 66.
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[0183] Fig. 69 shows a detailed sectional view of a prior art two side open
stab primer 300
such as generally specified as two side open stab primer 5 in Fig. 1 and
related figures.
A cylindrical metallic outer shell 301 open at the ends 307 and 308 encloses
an impact
and friction sensitive primer layer 302, a secondary ignition material layer
303 in
contact with primer 302, and a propellant layer 304 in contact with layer 303.
Layer
305 is paper or foil that protects primer layer 302, but is easily penetrated
during
ignition. A needle indicated schematically as 306 strikes and penetrates layer
304 and
then penetrates and ignites primer layer 302. Secondary ignition material
layer 303 in
turn ignites and heats and ignites propellant layer 304. (Jas is released from
both open
end 307 and open end 308 of shell 301. ~ne side open style stab primers (not
shown)
are contained in metal cups similar to shell 301, but closed on end 307, and
the gas is
released only from the side 308.
[0184] Fig. 70 shows a modular stab igniter 320 similar to the prior art
igniter 300 shown
in Fig. 69 but wherein an integral bistable spring 321 and firing pin 322
replace paper
or foil layer 305 and are enclosed in metallic shell 311 and held in
operational
relationship to impact and friction sensitive primer layer 302 by spacer ring
323. An
external force 324 pushes the center of bistable spring 321 so that it pops
through
center and drives firing pin 322 into primer layer 302, starting the ignition
process.
Secondary ignition material layer 303, in turn, heats and' ignites propellant
layer 304.
Gas is released from open end 307 of shell 311. Modular stab igniter 320 may
be
adapted by one skilled in the art to replace separate stab igniter and firing
pin ignition
systems in the injection devices described above with reference to Figures 1
to 68.
[0185] Fig. 71 shows a modular friction igniter 340 similar to the prior art
igniter 300
shown in Fig. 69 but wherein a friction firing pin 341 is incorporated. The
support disk
342, impact and friction sensitive primer layer 343, secondary ignition
material 344
and propellant 345 have central holes to receive friction firing pin 341, with
the hole in
the primer layer 343 being smallest. Friction firing pin 341 includes
serrations 346 that
rub strongly against the primer layer 343 as it is pulled out. Alternatively,
friction
firing pin 341 may be coated with abrasive grit and pyrotechnic material' (not
shown) in
place of serrations 346 to promote friction ignition. When friction firing pin
341 is
pulled, frictional interaction betwee~i the pin and the primer mix start the
ignition
process. Secondary ignition material layer 344 in turn ignites and heats and
ignites
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propellant layer 345. Gas is released from open end 307 of shell 301. Friction
firing
pin 341 may be pulled by a variety of mechanisms operated by the user to
trigger the
injection. Ivgodular friction igniter 340 is only an e~axnple, and other
friction pxixners
are possible. In particular, flexible fabric string with an abrasive coating
n~aay replace
the rigid friction firing pin 341. Modular friction igniter 340 may be adapted
by one
skilled in the art to replace separate stab igniter and firing pin ignition
systems in the
injection devices described above with reference to Figures 1 to 68.
[018G] The ignition means described above with reference to Figures 1 to 71
are also
suitable for other forms of pyrotechnically powered injection devices, and
such
applications are included in the scope of the invention.
[0187] Although preferred embodiments of the invention have been described
using
specific terms, such description is for illustrative purposes only, and it is
to be
understood that changes and variations may be made without departing from the
spirit
or scope of the following claims.
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RCH 110/00/W0
~aEi'~T~~ ~~T~1I~JH~~~ lll'~T ~.'~~L11T~-~
1 first embodiment injection
device
2 two side open stab primer
3 propellant chamber
4
firing pin
6 spring
7 release lever
breakable crimp joint
9 bore
cup seal
11 cup seal clearance hole
12 medication container
13 medication unit
14 flexible wall of medication
container 12
nozzle
16 fluid channel
17 orifice / jet outlet
1 deformable/elastic barrier
~
19 break-off protective cap
first housing part
21 second housing part
22 seat second housing part 21
23 free volume
24
26
27
2~ intermediate support member
29
screw conxiection of housing
parts
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31 first chamber
32 second chamber
33 first zone of first chamber 31
34 second zone of first chamber
31
35
36
37 second housing part
38 hole in second housing part 37
39 seat in second housing part 37
40 impact plunger
41 propellant chamber
42 stab pin
43 support bridge in propellant
chamber 41
44 flow passages
45 one side open stab primer
46 bore in propellant chamber 41
47 second embodiment injection device,
48 primer shell
49 free volume
50 third embodiment injection device
51 impact plunger
52 tapered section of impact plunger
51
53 hook of impact plunger 51
54 release lever of impact plunger
51
55 cylindrical guide sleeve of rear
housing 21
56 release latch ,
57 conical cavity in release latch
56
58 second housing part
59 hole in second housing part 58
60 fourth embodiment injection device
61 firing pin
62 bistable disk spring
63 actuation screw
64 propellant chamber
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65 outer edge of bistable disk
spring 62
66 seat in second housing part
58
67 hole in second housing part
68
68 second housing part ~8
69
70 fifth embodiment injection
device
71 bistable disk spring
72 vent holes in bistable disk
spring 71
73 activation push pin
74 rubber seal
75 second housing part .
76 outer edge of bistable disk
spring 71
77 hole in second housing part
75
78 enlarged head of activation
push pin 73
79
80 sixth embodiment injection
device
81 firing pin
82 seal bushing
83 propellant chamber
84 clearance holes in seal bushing
82
85 spring retainer washer
86 shoulder of firing pin 81
87 break region of bring pin 81.
88 release lever
89 front end of primer 2
90 rear end of primer 2 .
91 spring
92 connection joint
93 flange of firing pin 81
94 free volume
95 seal joint
96 second housing part
97
98
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99
100 seventh embodiment injection device
101 firing pin
102 spring
103 free voluane
104 propellant chamber
105 flange of firing pin 101
106 latch ears of firing pin 101
107 twist shaft of firing pin 101
108 shaft seal
109 second housing part
110 hole in second housing part 109
111 support shoulders of propellant
chamber 104
112 release grooves of propellant
chamber 104
113
114
115
116
117
118
119
120 eighth embodiment injection device
121 firing pin
122 twist shaft
123
124 flange of firing pin 121
125 latch ears of firing pin 121
126 clutch slot of firing pin 121
127 seal flange of twist shaft 122
128 hole in second housing part 130
129 clutch blade of twist shaft 122
130 second housing part
131 spring
132 free volume
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133
134
135
136
200 ninth embodiment injection device
201 firing pin
202 propellant chamber
203 ratchet grooves of firing pin 201
204 second housing
205
206 ratchet fingers
207 seal
208
209
210 free volume
211 external impact motion
212 annular volume
213
214
215
220 injection device with breakable membrane
221 breakable membrane
230 injection device with pyrotechnic module .
231 nozzle body .
232 rigid housing
233 volume enclosed by nozzle body 231 and rigid housing 232
234 first deformable diaphragm
235 cavity of nozzle body 231
236 medication chamber
237 medication
233 second deformable diaphragm
239 chamber enclosed by second deformable diaphragm 23~
and rigid housing 232
240 propellant and ignition means
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241 channel of nozzle body 231
242 orifice of nozzle body 231
243 vents
244 space between first def~arax~able diaphragm 234 and
second deformable diaphragm. 238
245 first deformable diaphragm
246 shell formed by nozzle body 231 and rigid housing 232
250 injection device with piston
251 rigid medication chamber
252 medication zone of rigid medication chamber 251
253 liquid medication
254 nozzle end of rigid medication chamber 251
255 outlet orifice
256 cylindrical bore of rigid medication chamber 251
257 rigid housing
258 cylindrical bore of rigid housing 257
259 drive piston
260 propellant zone formed by rigid housing 234 and
second deformable diaphragm 238
261 propellant and ignition means
262 medication piston
263
'264
270 ' injection device with pyrotechnic module
271 pyrotechnic module
272 connection
300 prior art two side open stab primer
301 metallic shell
302 impact and friction sensitive primer
303 secondary ignition material layer
304 propellant layer
305 paper or foil layer
306 schematic needle
307 first open end of metallic shell 301
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308 second open end of metallic
shell 301
320 modular stab igniter
321 bistable spring
322 firing pin
323 spacer ring
324 e~.ternal force
325
340 modular friction igniter
341 friction firing pin
342 support disk
343 impact and friction sensitive
primer layer
344 secondary ignition material
layer
345 propellant layer
346 serrations of friction firing
pin 341
347
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